Tapered Battery Current Collector for Flexible Terminal Routing

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Solution Overview

Problem

Current battery cell current collectors face limitations in dimension, placement, and resistance, which can lead to increased weight and localized heating issues when trying to accommodate varying terminal placements and space constraints within battery cells.

Innovation Solution

A current collector with a decreasing cross-sectional area along its path from the electrode assembly to the terminal, allowing for flexible terminal placement and reduced resistance, formed from sheet metal using machining and folding techniques, with angled sections to fit around corners and transition portions that can be stepped, chamfered, or curved to avoid collisions and maintain electrical properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the current collector uses a constant cross-sectional area, then the manufacturing is simpler, but the weight increases and localized heating occurs

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidcurrent collector weight
Core Design Contradiction:
Ease of manufactureVSWeight of moving object

Solution Approach 1:

The current collector employs a variable cross-sectional area design where different sections have different dimensions. The first section has a larger cross-sectional area for high current carrying capacity near the electrode assembly, while the second section has a smaller cross-sectional area reducing weight. This local variation optimizes both electrical performance and weight without requiring complex manufacturing processes.

Inventive Principle:
Principle #3Local quality

2Adaptability or versatility

If the terminal is placed at a distant location, then the flexibility of terminal placement is improved, but the current collector weight increases

Engineering Contradiction:
Improveterminal placement flexibilityVSAvoidcurrent collector weight
Core Design Contradiction:
Adaptability or versatilityVSWeight of moving object

Solution Approach 1:

The current collector is designed with a variable cross-sectional area that decreases along the current path from the electrode assembly toward the terminal. This allows the collector to extend over longer distances with reduced weight, as the smaller cross-sectional area sections contribute less mass while still providing adequate electrical connection at distant terminal locations.

Inventive Principle:
Principle #3Local quality

3Adaptability or versatility

If the current collector path is extended to reach distant terminals, then the terminal placement flexibility is improved, but localized heating increases

Engineering Contradiction:
Improveterminal placement flexibilityVSAvoidlocalized heating
Core Design Contradiction:
Adaptability or versatilityVSTemperature

Solution Approach 1:

The current collector features a non-uniform cross-sectional area distribution where the larger cross-sectional area is positioned at sections requiring higher current carrying capacity. This local optimization ensures that critical areas near the electrode assembly and high-current regions have sufficient conductive cross-section to minimize resistive heating, while allowing the collector to extend to distant terminals.

Inventive Principle:
Principle #3Local quality

4Weight of moving object

If the current collector cross-sectional area is reduced, then the weight is reduced, but the resistance increases

Engineering Contradiction:
Improvecurrent collector weightVSAvoidelectrical resistance
Core Design Contradiction:
Weight of moving objectVSReliability

Solution Approach 1:

The current collector employs a variable cross-sectional area design that strategically places larger cross-sections at locations requiring high current carrying capacity (near the electrode assembly) and smaller cross-sections where current demand is lower. This ensures that the overall resistance remains acceptable while achieving weight reduction, as the critical high-current paths maintain sufficient conductive area.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP4318784A1Current collector for a battery cell
Publication Date: 2024.02.07 NORTHVOLT AB
  • EP4318784A1 patent drawingFigure 1~2
  • EP4318784A1 patent drawingFigure 3A~3B
  • EP4318784A1 patent drawingFigure 4~5

AI summary

There is disclosed herein a current collector (300) for a battery cell, comprising a first section (302) comprising a first end (301) configured to connect to an electrode assembly of the cell, and a second section (304) angled relative to the first section (302) comprising a second end (303) configured to connect to a terminal of the cell. A current path is formed from the first end (301) to the second end (303), and a cross-sectional area of the current collector (300) decreases along the current path from the first end (301) to the second end (303) or from the second end (303) to the first end (301).